Chaelbs swett



y @uiten CHARLES SWET'IIIF VICKSBI'IRG, MISSISSIPPI.` Letters Patent No. 71,424, dated November 26, 1867.

ARTIFICIAL LEG.

TO ALL WHOM IT MAY CONCERN:

Be it known that I, CHARLES Swn'rr, of Vicksburg, in the county of Warren, and State of Mississippi, 1 have invented a new and useful Improvement in Artificial Leg and I do hereby declare that the following is a 11 full, clear, and exact description thereof, whichwill enable others skilled in the art to make and usethe samew reference being had to the accompanying drawings, forming part of this specification, in which Figure 1 is a central vertical section ot' a. leg, showing my improved ankle-joint.

Figure 2 is a transverse section taken in the plane of the line x, tig. 2. 1

Similar letters of reference indicate like parts. 1

This invention relates to an improved arrangement of devices for an ankle-joint of an artificial leg,and1 consists in a combination of a vertical spring with a horizontal Indiafrubber plate, arranged in such manner thatA the foot may readily adapt itself to any required position when a step ismade withthe artificial limb, throughg1w1 the combined exible action of the India-rubber plates and steel springs, while by theirA elasticity the movement will be assisted, and the foot will instantly resume its lnatural position when lifted from theground.

In fig. 1,.A is the leg and B the foot of an artificial limb, made of wood or any suitable material. The leg anll foot are made in separate pieces, divided transversely through the auklefjoint. On the lower end of `the 1 i* t section ofthe leg A is fastened a metal plate, a, in which is made a narrow slot,`b b, about one and one-quarter ,1

inch long, as shown in fig. 2. This slot is made at right angles to the central line of the foot, Vand throughit passes a ilat steel spring, c, about one inch in width, and varying in thickness with the strength and elasticitygw.;I

required in the case to which the limb is applied. The spring e is let intoa long recess inthe lower endottlie leg, corresponding to the slot b b in the plate a, in. the upper part4 ot' which recess it is held by a. pivbt, d, that passes from the'front to the back side ofthe leg A, in such manner that the spring c basa lateralmovement permitted from one end to the other of the slot b b. The lower end of the spring cis turned at right-angles, 11

andlet into the heel of the foot B, where it is firmly secured by screw-bolts and nuts e e, and binding-plates s s. 11 'The length of the spring c is such as to allow an India-rubber plate or cushion,`m, of proper consistency and 14 1 elasticity to be placed between the upper part of the foot B and the lower part of the leg A, next to the ,plate a, about one and one-quarter of an inch in thickness. In the rubber plate is a-slot corresponding to the slot b b, through which passes the spring c. For the purpose of giving local elasticity to the heel, I insert a horif zontal plate or cushion of India rubber, n, horizontally in the heel of -the `foot A, secured by one or more screws,` e', under a tap, i'. It will be obvious that with this combined arrangement of a horizontal rubber cushion and vertical spring in the ankle, the joint willhave-a free and elastic movement 4-in all directions, and especially V p v forward and backward, to facilitate the action of the limb in stepping and treading on the ground, and also, i laterally through the play of the spring edgewise'iin the slot 'b b, as su'spended'on the pivot d. The rubber plate 1 m should have holes cut before and behind the spring c, so as to leave a narrow strip on each side of it, and a 1 i l narrow rim around the outside of the plate, to produce more-elasticity. behind the ankle a thin `metal plate should be screwed, to connect the leg and heel together, and serve asia chec "-plate, being made fast 1 to the heel B, and slotted, to slide on the leg A. v 1

Having thus described my invention, I claim as new, and desire to secure by Letters Patent- 1 1 1. The at vertical spring c, combined with the horizontal rubber cushion m, the legA, and foot B, arranged 1 and operating substantially as and for the purposes herein described.

2. In combination with the above, I claim thc elastic cushion a, substantially as described for the purpose 1 specified.

CHAS. SWETT.

Witnesses:

C. A. Munson, -TonN H. HoBAnT. 

